- Aka OEIS (Omphalocele, Cloacal extrophy, imperforate anus, spinal defects)
- Persistence of cloaca- common channel receiving ureters, ileum and rudimentary blind ending hindgut
- Associated with omphalocele, spinal dysraphism, incompletely formed external genitalia and always imperforate anus
- Different from bladder extrophy where anal and spinal anomalies are rare